The invention relates to a dual clutch transmission comprising a first partial transmission and a second partial transmission, wherein a first group of forward gears is allocated to the first partial transmission and a second group of forward gears is allocated to the second partial transmission.
Dual clutch transmissions are used increasingly in motor vehicles. One advantage offered by dual clutch transmissions is the ability of shifting gears between two adjacent forward gears without interruption in the driving power. Two adjacent forward gears are defined as comprising transmission ratios where no transmission ratio of any other forward gears is in between. For achieving gear shifting without interruption in the traction force a first forward gear, third forward gear and a fifth forward gear are for example allocated to the first partial transmission, while the second forward gear, the fourth forward gear and the sixth forward gear are allocated to the second partial transmission. When shifting gears for example from the third forward gear into the fourth forward gear, it is for instance possible by an appropriate design to provide during the transition phase a torque transmission of both clutches of the dual clutch transmission during the transition period of shifting gears from the third into the fourth forward gear. This requires, however, that the adjacent gears are allocated to different partial transmissions.
The fixed allocation of the first group of forward gears to a partial transmission and of the second group of forward gears to the other partial transmission makes it more difficult to modify or supplement the dual clutch transmission. Therefore, it is generally not possible to configure by simple modifications of an existing dual clutch transmission a new dual clutch transmission. The described fixed allocation of the forward gears to the respective partial transmission may therefore require a completely new gear wheel set for adding another forward gear to the dual clutch transmission and therefore requires major efforts. These efforts might increase further for creating a new gear wheel set if the packaging of the motor vehicle allows only for a limited space for the dual clutch transmission. This is in particular the case in motor vehicles where the motor is installed in a transverse direction where the axial installation height is critical.